Summary
This HOW TO is divided into three sections. The first is the xsetwacom MapToOutput Method for tablets on the Wacom drivers. MapToOutput has been extended to apply to the Nvidia proprietary driver, i.e. TwinView starting with the xf86-input-wacom-0.12.0 release. The second is the Coordinate Transformation Matrix Method which works for all tablets. The third deals with getting either method to work through a reboot. Tablet PC rotation with CTM is in appendix 1.

Note: There is a X Server bug that prevents CTM from working correctly with xf86-input-evdev. If you apply a CTM to a input tool that uses xf86-input-evdev the associated cursor jumps around. Spurious lines are drawn in Gimp, Inkscape, etc. This is fixed in X Server 1.13.0. See Bugzilla Bug 49347. It's not clear which X Server version this bug first appeared in although it appears to affect at least the 1.11, 1.12 (Maya/Precise), and probably the 1.10 series.

I. xsetwacom MapToOutput Method - for Tablets using the xf86-input-wacom driver: Hanwang, N-trig, Wacom, & Waltop
The nice thing about MapToOutput is it does all of the matrix calculations for you automatically.

1) You must have xf86-input-wacom 0.10.9 (0.10.8+ after the 8-11-10 commit "xsetwacom: add "MapToOutput" parameters."; the default in Maverick is 0.10-8 ) if you have a 32-bit install. Otherwise if you have a 64-bit install you must have xf86-input-wacom 0.10.10+ (after the 1-11-11 commit "xsetwacom: fix 64-bit issues with MapToOutput").

First determine the "device name" of what you want bound on a specific screen. Your choices will be the stylus, eraser, or cursor (Wacom tablet mouse). In a terminal enter:

and select the name of the monitor, among the monitors you see in the output, that you would like the device on. Substitute that monitor name for VGA1 in the command. Using your "device name" (in quotes) from 'xinput list' you can now use the xsetwacom command:

2) TwinView (NVidia proprietary driver binary). Support was added with the "xsetwacom: Support MapToOutput for TwinView" commit on 6-23-11 (in the 0.11.99+ tree) and is available in the xf86-input-wacom-0.12.0 release tar.

Choose the monitor you want the input tool on using "HEAD-0", "HEAD-1", etc., e.g.:

Note: the above MapToOutput commands only apply to the current xrandr configuration, they will need to be re-applied with a restart (or rotation). So you'll have to set up the xsetwacom MapToOutput command(s) in a startup script. See below.

II. Coordinate Transformation Matrix Method - for all Tablets
While the following may seem a little daunting if you look at the examples you'll find it is not that hard. The code does the matrix multiplication for you. You are determining the matrix values by solving fractions involving your monitors' dimensions.

First determine the "Device name" of what you want bound on a specific screen. Your choices will be the stylus, eraser, or cursor (Wacom tablet mouse). In a terminal enter:

which has the effect of multiplying by 1, or in other words no transformation, the addition of a third vector value (beyond X & Y) makes it an affine transformation with homogeneous coordinates. We need to determine the transform matrix appropriate to the monitor you want to place the device on.

What we will do with the transform is translate the currently assigned pixel coordinate vector X,Y of your tablet device to a new pixel coordinate vector X',Y'.

The numbers in the X server "Coordinate Transformation Matrix" are a 3x3 matrix read out row by row. Using an affine transformation means translation can be expressed with matrix multiplication. The equation we are looking at is in the form of:

Now if we rotate to tablet mode we are adding a rotational transformation. Let's use rotation by an angle A counter-clockwise about the origin. The functional form would be x' = xcosA − ysinA and y' = xsinA + ycosA but we want to make it affine so we can use multiplication. And we need to add it to the current matrix. So written in matrix form, it becomes something like:

II. Three Monitors - simple case
Three monitors with the same resolution. You set up the linear transform and since we're scaling from 0-1 if all three monitors have the same resolution you'd end up with:

III. To Have the Settings Last Through a Reboot
You have to apply the xinput or xsetwacom command with each restart. You should be able to add it to your xsetwacom start up script, if you have one. Otherwise run it from a convenient start up script. Sample start up scripts are attached to posts 1 & 2 of the Wacom Bamboo Pen and Touch tablet HOW TO thread. Add the appropriate command for each device (stylus, eraser, and cursor) to its section.

To set it up to auto-start, download a sample file or make your own, and rename it .xsetwacom.sh (or whatever you want) and place it in your home directory. Remember it will be a hidden file. To enable the xsetwacom commands in the .xsetwacom.sh file to apply to Xserver through a reboot you enter in a terminal:

or you could right click on the file and in Properties, in the Permission tab, check Execute as program. Then go to System->Preferences->Startup Applications and click on add and for the command write "sh /home/yourusername/.xsetwacom.sh" (without the quotes). You can also change your settings on the fly using the xsetwacom parameters in a terminal. They only apply during the current session.

Once the script is executable you can double click on it to apply it's settings or reboot to check the auto-start set up.

Note: In the sample scripts both "device name" and ID # are used. Be sure to check for yours using 'xinput --list' (without the quotes) in a terminal and use them. When you use a xorg.conf the "device names" will be stylus, eraser, touch, and pad. If you are hot plugging your tablet or other devices be sure to use "device name" as the ID # can change.

Appendix 1 - Tablet PC Rotation with CTM
Rather than axis inversion and swap for evdev rotation the CTM method can be used instead.